This invention relates to a driving device for a bicycle, and more particular to a driving device without driving chain for the bicycle.
Conventionally, front and rear gears and a driving chain build up a driving device for a bicycle. The driving device includes a front gear comprising one or more sprockets mounted to a crank shaft, a rear gear comprising one or more sprockets mounted to a rear hub, and a driving chain stretched across both the front and rear gears. In riding, the driving chain is maintained across the front and rear gears under pressure in upper portion and loosely in lower portion thereof that may render the front gear to slip under some circumstances such as struggling up along a slope and the driving chain to disengage and thus separate from the gears. To this end, the inventor has attempted to provide an inventive driving device without a driving chain for a bicycle to overcome the drawbacks of known driving devices.